On closed sets of relational constraints and classes of functions closed under variable substitutions

Abstract

Pippenger's Galois theory of finite functions and relational constraints is extended to the infinite case. The functions involved are functions of several variables on a set $A$ and taking values in a possibly different set $B$, where any or both of $A$ and $B$ may be finite or infinite.

arXiv admin note: text overlap with arXiv:0810.3212